Patent literature 1 discloses an example of an operation management system which generates a model of a system by using time-series information on system performance, and detects a fault of the system by using the generated model.
The operation management system described in the Patent literature 1 determines a correlation function for each of combinations among a plurality of metrics (performance indexes) of a system on the basis of measurement values of the plurality of metrics, and generates a correlation model including a plurality of correlation functions each of which indicates a correlation. Then, the operation management system detects destruction of the correlation (correlation destruction) on the basis of newly inputted measurement values of the metrics by using the generated correlation model, and judges a fault cause on the basis of the detected correlation destruction. The above-mentioned art to analyze a fault cause on the basis of the correlation destruction is called an invariant analysis.